An “on–off” switchable cubic phase with exceptional thermal stability and water sorption capacity

2017 ◽  
Vol 53 (99) ◽  
pp. 13217-13220 ◽  
Author(s):  
K. N. Grafskaia ◽  
D. V. Anokhin ◽  
B. I. Zimka ◽  
I. A. Izdelieva ◽  
X. Zhu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Columnar Structure ◽  
Cubic Phase ◽  
Water Sorption Capacity

A wedge-shaped mesogen reveals structural bistability; the gyroid phase exhibits exceptional water sorption capacity whereas the columnar structure does not swell.

Experimental Design of Surface Modification of Expanded Obsidian and Determination of Water Sorption Capacity

2014 ◽  
Vol 1020 ◽  
pp. 823-826
Author(s):  
G.Sh. Hovsepyan ◽  
M.A. Kalantaryan ◽  
T.V. Yedoyan
Keyword(s):  
Experimental Data ◽  
Surface Modification ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Structural Changes ◽  
Ir Spectrometry ◽  
Water Capacity ◽  
Series Of Experiments ◽  
Water Sorption Capacity

The aim of this paper is to study the possibility of expanded obsidian and its modified product use for oil sorption, in that tetraethoxisilane (TEOS) has been used as a modifier. The optimal concentration of the modifier was determined by 50 per cent weight of expanded obsidian. The expanded obsidian was previously activated with 0,1 M solution of hydrochloric acid. IR spectrometry was used to characterise structural changes in the modified expanded obsidian samples. To determine water sorption capacity a series of experiments has been carried out. The analysis of obtained experimental data showed that after surface modification of expanded obsidian water capacity is reduced 3 times after the surface modification of EO.

scholarly journals Assessment of Performance of Posidona oceanica (L.) as Biosorbent for Crude Oil-Spill Cleanup in Seawater

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Senda Ben Jmaa ◽  
Amjad Kallel
Keyword(s):  
Crude Oil ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Pure Water ◽  
Water System ◽  
Oil Concentration ◽  
Oil Water ◽  
Mixed Oil ◽  
The Impact ◽  
Water Sorption Capacity

The marine environment is constantly at risk of pollution by hydrocarbon spills that requires its cleanup to protect the environment and human health. Posidonia oceanica (L.) (PO) beach balls, which are characteristic of the Mediterranean Sea and abundant on the beaches, are used as biosorbent to remove hydrocarbons from the sea. The impact of several factors such as oil concentration, time sorption, and weight sorbent was investigated to determine the oil and water sorption capacity for raw and milled P. oceanica fibers. The study of kinetic models for initial crude oil concentration of 2.5, 5, 8.8, 10, 15, 20, 30, and 40 g/L revealed that crude uptake followed the pseudo-first-order model while, for isotherm models, the crude uptake onto the P. oceanica tended to fit the Langmuir model. Experiments were performed according to two systems: a pure oil and pure water system and a mixed oil/water system. For the dry system (pure oil and pure water), the maximum oil and water sorption capacity of raw and milled fibers was found to be 5.5 g/g and 14 g/g for oil and 14.95 g/g and 15.84 g/g for water, respectively, whereas, in the mixed oil/water system, the maximum oil and water sorption capacity was estimated as 4.74 g/g, 12.80 g/g and 7.41 g/g, 8.31 g/g, respectively. The results showed that, in spite of their absorbency of a lot of water, the milled fibers with grain size ranging between 0.5 mm and 1 mm might be the relevant sorbent for the elimination of crude oil from seawater thanks to its efficient sorption capacity and low cost.

scholarly journals The influence of the ammonia concentration and the water content on the water sorption behavior of ambient pressure dried silica xerogels

2020 ◽  
Vol 96 (1) ◽  
pp. 197-206
Author(s):  
Lukas Huber ◽  
Silvia Paz Comesaña ◽  
Matthias M. Koebel
Keyword(s):  
Water Content ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Ambient Pressure ◽  
Ammonia Concentration ◽  
Silica Xerogel ◽  
Sorption Behavior ◽  
Relative Pressure ◽  
Silica Xerogels ◽  
Water Sorption Capacity

Abstract Porous silica xerogels were synthesized within 10 h by a two-step sol–gel process under atmospheric conditions. In the first step, tetraethylorthosiloxane (TEOS) was hydrolyzed with water using sulfuric acid as a catalyst. In the second step, water and ammonia were added to the prehydrolyzed silica sol prior to the drying of the samples at 150 °C. The influence of the ammonia concentration and the water content on the physicochemical properties and the water sorption behavior of silica xerogels produced in the aforementioned way was investigated. The resulting silica xerogels were characterized by helium pycnometry, scanning electron microscopy, fourier-transform infrared spectroscopy, nitrogen sorption, and water sorption. It was shown that a higher ammonia concentration leads to an increased pore size of the silica xerogel which starts to adsorb water at a higher relative pressure. With an increased water content during gelation, the silica xerogel has a higher specific surface area and a higher water sorption capacity. Furthermore, silica xerogels can be tailored by a controlled addition of ammonia and water to have a higher water sorption capacity than the reference silica gel over the whole range of relative pressure.

scholarly journals New Composite Water Sorbents CaCl2-PHTS for Low-Temperature Sorption Heat Storage: Determination of Structural Properties

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 27 ◽  
Author(s):  
Alenka Ristić ◽  
Nataša Zabukovec Logar
Keyword(s):  
Electron Microscopy ◽  
Calcium Chloride ◽  
Structural Properties ◽  
Sorption Capacity ◽  
Water Uptake ◽  
Water Sorption ◽  
Heat Storage ◽  
Impregnation Method ◽  
Sorption Heat ◽  
Water Sorption Capacity

Sorption heat storage, as one of low-energy consuming technologies, is an approach to reduce CO2 emissions. The efficiency of such technology is governed by the performance of the applied sorbents. Thus, sorbents with high water sorption capacity and regeneration temperature from 80 to 150 °C are required. Incorporation of hygroscopic salt such as calcium chloride into porous materials is a logical strategy for increasing the water sorption capacity. This work reports the study on the development of composites with PHTS (plugged hexagonal templated silicate) matrix with an average pore size of 5.7 nm and different amounts of calcium chloride (4, 10, 20 wt.%) for solar thermal energy storage. These composites were prepared by wetness incipient impregnation method. Structural properties were determined by X-ray diffraction (XRD), nitrogen physisorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). CaCl2 was confined in micro- and mesopores of the matrix. The resulting CaCl2-PHTS materials were used for water sorption at 40 °C, showing an increase of maximal water uptake with higher amount of calcium chloride from 0.78 g/g to 2.44 g/g of the dry composite. A small reduction in water uptake was observed after 20 cycles of sorption/desorption between temperatures of 140 °C and 40 °C, indicating good cycling stability of these composites under the working conditions.

scholarly journals INVESTIGATION OF HEMP WATER SORPTION CAPACITY / NATŪRALIŲ ORGANINIŲ KANAPIŲ SPALIŲ SORBENTO NAFTOS PRODUKTAMS ŠALINTI TYRIMAS

2016 ◽  
Vol 8 (4) ◽  
pp. 397-402
Author(s):  
Eglė Budriūtė ◽  
Vaidotas Vaišis ◽  
Donatas Mikulskis
Keyword(s):  
Sorption Capacity ◽  
Water Sorption ◽  
Textile Industry ◽  
Oil Spills ◽  
Plant Biomass ◽  
Renewable Resource ◽  
Raw Material ◽  
Industry Waste ◽  
Oil Water ◽  
Water Sorption Capacity

Effective clean-up of oil spills due to their negative environmental and economic impact is of capital importance. Clean-up of oil by sorption is considered one of the most desirable choices, because oil can be completely removed without causing any secondary pollution. Natural organic sorbents had been investigated and developed to control oil products‘ spills. Plant biomass is a renewable resource which can be converted into various materials and energy. Hemp (USO-31), as a textile industry waste, was used as an oil product sorbent material. The present study examines hemp sorption capacity of water using different fractions of hemp raw material to be used in oil/water mixtures. The experimental research revealed that water sorption capacity depends on fraction size and sorption time. The results of water sorption capacity of 2.5 and 5.0 mm after 1440 min were 4.74 and 4.67 g water/g dry sorbent, respectively. Labai svarbu efektyviai likviduoti išsiliejusius naftos produktus dėl jų neigiamo poveikio aplinkai ir ekonomikai. Naftos produktų valymo metodas pasitelkiant sorbentus yra laikomas vienu iš geriau­sių pasirinkimų, nes produktai yra absorbuojami sorbentų, nesukeliant jokios antrinės taršos. Natūralūs organiniai sorbentai buvo tiriami ir tobulinami, siekiant kontroliuoti naftos produktų išsiliejimus. Augalų biomasė yra atsinaujinantis išteklis, kuris gali būti naudojamas įvairioms medžiagoms ir energijai išgauti. Kanapių spaliai (USO-31), tekstilės pramonės atlieka, buvo tiriami kaip naftos produktų sorbentas. Buvo išnagrinėta kanapių vandens sorbcija naudojant įvairias šios medžiagos frakcijas. Eksperimentinis tyrimas parodė, kad vandens sorbcija priklauso nuo frakcijos dydžio ir sorbcijos laiko. Tyrimų metu buvo nustatyta vandens sorbcijos geba – 4,74 ir 4,67 g vandens/g sauso sorbento 2,5 ir 5,0 mm pavyzdžiams po 1440 min atitinkamai.

scholarly journals Effect of degree of crystallinity and the contents of aluminium oxide and sodium oxide on water sorption capacity in NaY zeolite

2016 ◽  
Vol 70 (4) ◽  
pp. 399-407 ◽  
Author(s):  
Dragana Keselj ◽  
Dragica Lazic ◽  
Zivan Zivkovic ◽  
Branko Skundric ◽  
Jelena Penavin-Skundric ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Regression Analysis ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Linear Regression Analysis ◽  
Degree Of Crystallinity ◽  
Quadratic Model ◽  
Nay Zeolite ◽  
The Degree Of Crystallinity ◽  
Water Sorption Capacity

The paper presents mathematical models which describe the dependence between water sorption capacity, on one hand, and the degree of crystallinity and the content of Na2O and Al2O3 in NaY zeolite, on the other. NaY was synthesized from sodium aluminate solution, water glass and sulfuric acid under different conditions of crystallization. The obtained zeolite powders underwent chemical analysis (Na2O, Al2O3), water sorption capacity (WSC), as well as diffraction analysis which served to determine the degree of crystallinity (CD). Zeolite powder samples had the following values: for the content of Na2O from 13.81 to 16.14%, for Al2O3 from 21.58 to 27.17%, degree of crystallinity from 58.70 to 114.00 and WSC from 21.32 to 36.59%, and regression analysis lead to the conclusion that there is a significant correlation between water sorption capacity and the degree of crystallinity, unlike the contents of Na2O and Al2O3 in the zeolite powder, whose correlation with water sorption capacity was neglibile. The mathematical model obtained by linear regression analysis had a high R2= 0.796, where as non-linear regressional analysis produced a better mathematical model R2= 0.912, where water sorption capacity was expressed through a quadratic model.

scholarly journals 3D Printing High-Consistency Enzymatic Nanocellulose Obtained from a Soda-Ethanol-O2 Pine Sawdust Pulp

2019 ◽  
Vol 6 (3) ◽  
pp. 60 ◽  
Author(s):  
Kangas ◽  
Felissia ◽  
Filgueira ◽  
Ehman ◽  
Vallejos ◽  
...  
Keyword(s):  
3D Printing ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Three Dimensional ◽  
Moisture Sorption ◽  
Wound Dressings ◽  
Pine Sawdust ◽  
High Consistency ◽  
Tissue Models ◽  
Water Sorption Capacity

Soda-ethanol pulps, prepared from a forestry residue pine sawdust, were treated according to high-consistency enzymatic fibrillation technology to manufacture nanocellulose. The obtained nanocellulose was characterized and used as ink for three-dimensional (3D) printing of various structures. It was also tested for its moisture sorption capacity and cytotoxicity, as preliminary tests for evaluating its suitability for wound dressing and similar applications. During the high-consistency enzymatic treatment it was found that only the treatment of the O2-delignified pine pulp resulted in fibrillation into nano-scale. For 3D printing trials, the material needed to be fluidized further. By 3D printing, it was possible to fabricate various structures from the high-consistency enzymatic nanocellulose. However, the water sorption capacity of the structures was lower than previously seen with porous nanocellulose structures, indicating that further optimization of the material is needed. The material was found not to be cytotoxic, thus showing potential as material, e.g., for wound dressings and for printing tissue models.

scholarly journals Metal- and Halide-Free, Solid-State Polymeric Water Vapor Sorbents for Efficient Water-Sorption-Driven Cooling and Atmospheric Water Harvesting

2021 ◽  
Author(s):  
Mengchun Wu ◽  
Renyuan Li ◽  
Yusuf Shi ◽  
Mustafa Altunkaya ◽  
Sara Aleid ◽  
...  
Keyword(s):  
Water Vapor ◽  
Solid State ◽  
Sorption Capacity ◽  
Toxic Metals ◽  
Water Sorption ◽  
Water Harvesting ◽  
Atmospheric Water ◽  
Solid Sorbents ◽  
State Water ◽  
Water Sorption Capacity

Metal- and halide-free, solid-state water vapor sorbents are highly desirable for water-sorption-based applications, because most of the solid sorbents are suffering from low water sorption capacity or toxic metals, while...

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